The invention concerns a structural component consisting of fibre-reinforced thermoplastic plastic as well as a method for manufacturing such a structural component and an installation for implementing this method.
Such known fibre-reinforced preformed-and structural components in general can be manufactured either with cost-effective series production methods and with only a relatively low fibre reinforcement, with which-while a broad variety of shapes is possible-load-bearing functions cannot be accomplished. Or else relatively a expensive, elaborate methods with a high proportion of continuous fibre are called for, which enable structural components for demanding load-bearing functions, whereby the forming here, however, frequently is limited, resp., would once again require an increased expenditure. With the known cost-effective manufacturing methods, short- or long-fibre-reinforced preformed components can be produced with a relatively low proportion of fibre and correspondingly limited mechanical characteristics, such as strength, rigidity, brittleness and creep behaviour. Such methods are, e.g., short-fibre injection moulding, which makes possible a very good shaping, but which as a result of the very limited fibre lengths utilizable (usually less than 3 mm) and the comparatively low proportions of reinforcing fibres, however, are mechanically still relatively weak and brittle. In the case of a further known method, the long-fibre extrusion, greater fibre lengths of over 5 mm, e.g., 10-30 mm are possible, which with a good consolidation in part make possible improved mechanical characteristics, above all also reduced thermal expansions. Various methods for the suitable corresponding-to-form feeding in of the long-fibre molten mass are known, e.g., by means of conveyor belts and blades for separating the molten mass in the mould or by means of a controlled laying device in accordance with EP 769 358.
With a corresponding-to-form feeding in, short flow paths and careful treatment of the long-fibres can be achieved. However, also with this no load-bearing structures are feasible. In particular demanding load-bearing structural components, such as, e.g., for vehicle cabins, chassis components or load-bearing body components or also for light, but stable transport containers, sports implements, etc., cannot be manufactured with this known method. In addition to the high mechanical requirements of load-bearing structural components in vehicle manufacture, apart from high strength values above all also a high creep resistance and a favourable crash characteristic with a defined adjustability and a high energy absorption are demanded. Such demanding load-bearing structural components are feasible with continuous fibre-reinforced composite components, however, they call for very elaborate, expensive manufacturing processes. These are, e.g., the squeeze moulding of plane thermoplastic continuous fibre semi-finished products (organo-sheet pressing), which, however only allows a limited shaping or else requires a once again increased effort for a more elaborate shaping. Also load-bearing structural components made of high-strength duromer composite materials can only be produced by elaborate and expensive processes, in general require relatively long cycle times and also with respect to re-cycling lead to additional problems. They are therefore not utilizable for larger series in vehicle production.
It is therefore the object of the invention presented her to overcome these limitations, resp., disadvantages of the known methods and structural components and to create a load-bearing structural component as well as a corresponding manufacturing method and to indicate an installation for the manufacture of a structural component, which can reliably fulfil demanding load-bearing functions and which structural component can be manufactured cost-effectively and in different shapes, whereby also short cyle times for a series production can be achieved. Over and above, also additional functions, such as, e.g. the introduction of forces into the structural component shall be possible.
With the invention, in essence advantageous characteristics of long-fibre compression-moulded components, which make possible a broad range of shapings, combined with the high mechanical characteristics, which form the integrated load-bearing supporting structure with at least one load-transmitting internal connecting area of the coninuous fibre strands, in that in a simple manner in one manufacturing process relatively cost-effectively and with short cycle times light and load-bearing structural-and preformed components can be made.
The dependent claims concern advantageous further developments of the invention, which for various applications make possible particular advantages with respect to producibility, mechanical characteristics, weight and manufacturing costs as well as additional functions.